I'm editing the entire post to show the problem:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<link type="text/css" href="./jQuery/jQueryUI/css/ui-darkness/jquery-ui-1.8.4.custom.css" rel="stylesheet" />
<script type="text/javascript" src="./jQuery/jquery-1.4.2.min.js"></script>
<script type="text/javascript" src="./jQuery/jQueryUI/js/jquery-ui-1.8.4.custom.min.js"></script>
<script type="text/javascript">
$(function() {
var availableTags = ["ActionScript", "AppleScript", "Asp", "BASIC", "C", "C++", "Clojure", "COBOL", "ColdFusion", "Erlang", "Fortran", "Groovy", "Haskell", "Java", "JavaScript", "Lisp", "Perl", "PHP", "Python", "Ruby", "Scala", "Scheme"];
$("#tags").autocomplete({
source: availableTags
});
});
</script>
</head>
<body>
<br/><br/><br/>
<div id="LoginLinkSearch" class="ui-widget">
<label for="tags">Tags: </label>
<input id="tags" />
</div>
<br/><br/><br/>
</body>
</html>
I was experiencing problems in other browsers, but I believe this is due to me using a bad CSS file for the jqueryUI.